Circulating valve



Jan. 9, 1962 J. G. SPALDING CIRCULATING VALVE 4 Sheets-Sheet 1 Filed May26, 1958 James G. Spolding Filed May 26, 1958 4 Sheets-$heet 2 INVENTORJames G. Spalding ATTORNEY IN w qm a 2 T a n w w Fig. 2

Jan. 9, 1962 J. G. SPALDING 3,016,096

CIRCULATING VALVE Filed May 26, 1958 4 Sheets-Sheet 5 K L I A X V A/ XF. 7 INVENTOR 9 James G. Spulding Jan. 9, 1962 J. G. SPALDINGCIRCULATING VALVE 4 Sheets-Sheet 4 Filed May 26, 1958 INVENTOR Fig.9

James G. Spulding ATTORNEY Fig.8

3,016,096 CIRUULATING VALVE 7 James G. Spaiding, Calgary, Alberta,Canada, assignor to Otis Engineering (Jorporation, Dallas, Tern, acorporation of Delaware Filed May 26, 1953, Ser. No. 737,616

Claims. ,(Cl. 166-224) This invention relates to well tools and moreparticularly to a device for preventing undesired upward flow through awell pipe.

In the conventional method of drilling a well, a weighted fluid ordrilling mud is pumped downwardly through the drill pipe and the drillbit and thence upwardly outwardly of the drill pipe through the drilledhole to the surface of the earth as drilling progresses. The drillingmud serves, among other things, to lubricate the bit, to convey thecuttings to the surface, and to serve as a hydrostatic plug to containand retain any high pressures suddenly released by the penetration ofthe drill bit into an earth formation containing fluid or gas under highpressure.

In some cases it is desirable to conduct rotary drilling operationsusing air or gas (referred to generally as air) as a drilling fluid,circulating the air in the same manner as the drilling mud isconventionally circulated. The air performs the same functions generallyas the drilling mud, except that it offers no protection against therelease of pressure into the well from a high pressure formation. If thehigh pressure is not retained within the well, fluids or gas will beforced in an uncontrolled manner therefrom in what is known as ablowout."

When rotary drilling is being performed, a blowout preventer or similardevice at the surface is customarily provided whereby the annular spacebetween the drill pipe and the drilled hole may be closed. When air isused as a drilling medium, it is necessary to provide a means wherebythe drill pipe itself may be closed to flow from below in order tocompletely protect against a blowout.

It is therefore one object of this invention to provide a circulatingvalve in a drill string for closing a well to flow from below.

Another object is to provide a valve of the character described whereinthe valve is quickly and easily closable, and, particularly, acirculating valve which is closable simply and quickly by a lifting ofthe drill pipe.

A still further object is to provide a device of the character describedwhich is capable of transmitting the torque necessary for rotarydrilling.

Yet another object is to provide a device of the character describedwherein fluids may be forced downwardly therethrough even when thedevice is closed to flow from below.

A further object is to provide a device of the character describedwherein the operating parts of the device are not subject to erosion bythe normal downward'flow of fluids through the device. I

Another object is to provide a device of the character described whereinat least a part of the device is removable upwardly through the wellpipe.

A still further object is to provide a device of the character describedwherein, when a part of the device is removed from the well pipe, thebore of the well pipe is unrestricted so that other devices or welltools may be passed therethrough.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of a deviceconstructed in accordance with the invention, and reference to theaccompanying drawings thereof, wherein:

Patented Jan. 1962 FIGURES 1 and 1a, taken together, constitute a view,partly in section and partly in elevation, of the circulating valveinstalled in the drill pipe of a well being drilled;

FIGURES 2, 3 and 4, when taken together, constitute an enlarged view,partly in section and partly in elevation, showing the circulating valveopen in the drill pipe to permit normal downward flow of drilling fluidtherethrough;

FIGURE 5 is a cross-sectional view taken on the line 5-5 of FIGURE 2;

FIGURE 6 is a cross-sectional view taken on the line 6-6 of FIGURE 4;and,

FIGURES 7, 8 and 9, when taken together, constitute a view similar tothat of FIGURES 2 through 4, showing the circulating valve closed in thedrill pipe to prevent upward flow therethrough.

Referring now particularly to FIGURES l and la of the drawings, thenumeral 10 refers to a circulating valve which is connected to the lowerend of the lowermost of a plurality of upper heavily-walled sections ofpipe or drill collars 11 and to the upper end of a plurality of similarlower drill collars 11a. The uppermost drill collar 11 is in turnconnected at its upper end to a string of drill pipe 12 and thelowermost drill collar 11a is connected at its lower end to a drill bit13 to make up a drilling string 13a.

A string of large diameter pipe or casing 14 is installed and cementedin the drilled hole 15, and the customary flanged fitting or casing head16 is provided at the upper end of the Well casing. A valve 17, known asa master valve, is installed atop the casing head and is openable toadmit the drilling string and is closable to close off the well when thedrilling string is removed.

A pipe T or drilling spool 19 mounted on the master valve is providedwith a lateral or flow line outlet 23, and a blowout preventer .18 ismounted atop the drilling spool. The blowout preventer may be similar toany wellknown type of blowout preventer and is adapted to be opened topass the drilling string into and from the well and to be closed aroundthe string of drill pipe to positively close the annular space 18abetween the drill pipe and the well casing against flow therethrough. Arotating seal drilling head 20, such as that shown in the Patent No.2,105,754 to H. C. Otis, is installed atop the blowout preventer toeffect a continuous seal with the outer surface of the drill pipe.

A flow line valve 22 is installed on the flow line outlet 23 of thedrilling spool, and a flow line 24 is attached to the valve forconducting the fluids flowing therethrough away from the well.

Drilling operations are conducted in the usual manner; that is, adrilling medium such as air or gas is forced into and downwardly throughthe drill pipe by means of a compressor and a flexible connection (notshown) to the upper end of the string of drill pipe. The air or gasflows downwardly through the drill pipe and the circulating valve andthrough the drill bit to the bottom of the well, and returns upwardly tothe surface through the annular space 18a between the drilling stringand the drilled hole to the flow line outlet 19 and the flow line 24.The blowout preventer 18 and the master valve 17 are open to permitready passage of the drilling string therethrough and rotation thereinand so facilitate the return flow of air upwardly between the drillingstring and the casing. The rotating seal drilling head 20 is closedaround the drill pipe to insure that the return flow of air is directedoutwardly only through the open flow line valve 22 and the flow line 24.The return flow Referring now to FIGURES 2 through 9 of the drawings,the circulating valve it includes a tubular body or inner sleeve 25which is threaded at its upper end to an upper sub 26 which is in turnthreaded to the lower end of the lowermost drill collar 11. A pluralityof external splines 27 are formed on the upper part of the inner sleevebelow its connection to the sub 26 for mating engagement by a similarplurality of internal or inner splines 28 formed in the upper end of atubular housing or outer sleeve 29. The length of the internal splinesof the outer sleeve is less thanthat of the external splines of theinner sleeve so that the splines constitute means which permit the innerand outer sleeves to move longitudinally relative to one another in atelescoping fashion while preventing rotation of the sleeves relative toone another.

A downwardly facing shoulder 30 at the lower end of each of the internalsplines 28 engages with an upwardly facing external annular shoulder 31on the inner sleeve below the external splines to limit downwardmovement of the outer sleeve on the inner sleeve, while the engagementof the upper end 32 of the outer sleeve with the upper sub 26 limitsupward movement of the outer sleeve on the inner sleeve.

A lower sub 33 (FIGURE 4) is threaded into the lower end of the outersleeve and is in turn threaded to the upper end of the uppermost drillcollar 11a. A screw 34 threaded into a suitable lateral bore 34a of thesub retains the threaded connection between the outer sleeve and thelower sub against inadvertent release. The tubular sleeves 25 and 29 ofthe circulating valve thus provide an open fluid passageway between theupper and lower drill collars.

A tubular mandrel or landing nipple 35 having a bore diameterapproximating that of the drill pipe 12 is threaded into the upper endof the lower sub and ex tends upwardly within the inner sleeve. Theouter diameter of the nipple is reduced substantially from the innerdiameter of the inner sleeve whereby an annular fiow course 35a isprovided around the upper end of the nipple within the inner sleeve. Aplurality of lateral windows 36 are provided through the Wall of thenipple at a point spaced above its lower end for a purpose to be morefully hereinafter described. An internal annular landing and locatinggroove or recess 37 is provided in the bore of the nipple at a pointspaced above the windows 36, and an internal annular locking groove orrecess 38 is also formed in the bore of the nipple at a point spacedabove the landing and locating recess. The locking groove and thelanding and locating recess are provided for the installation of adownwardly opening check valve 44 in a. manner and for a purpose to bemore fully hereinafter described.

A packing sub 39 is threaded into the lower end of the inner sleeve 25and surrounds the nipple. A packing means 40, shown to be of a pluralityof oppositely facing rings of the V or Chevron type, is provided in anenlarged lower part of the bore of the packing sub and is retainedagainst an internal annular downwardly facing shoulder 41 of the packingsub by a spacer ring 42 and a' packing gland l-S threaded into the lowerend of the packing sub, The packing meansrnanifestly seals between thepacking sub and the outer surface of the landing nipple.

The length of the packing sub, the location of the packing means 40 inthe sub, and the location of the windows 36 of the landing nipple aresuch that, when the outer sleeve is in its upper position on the innersleeve as shown in FIGURES '2, 3 and 4, the windows are disposed abovethe upper end of the packing sub. When the inner sleeve is in its lowertelescoped position on the inner sleeve as shown in FIGURES 7, 8 and 9,the windows of the landing nipple are moved downwardly within thepacking sub below the packing means. Flow from (-k around the landingnipple can thus take place inwardly through the windows and downwardlythrough the landing nipple when the outer sleeve is in its upperextended position, but inward fiow through the windows is prevented bythe sealing engagement of the packing means with the landing nipple whenthe outer sleeve is in its lower position and the windows are below thepacking means.

It is noteworthy that, when the outer sleeve is in its upper position,the lower edges or faces of the windows through the landing nipple arelocated above the upper end of the packing sub, FIGURE 4, whereby noerosion of any sealing surfaces may take place because of the flow offluids through the windows.

The downwardly opening check valve provided for installation in thelanding nipple includes a locking and sealing device 45 of the characterillustrated in the patent to John V. Fredd for Well Devices, No.2,798,559, and a check valve assembly 44 threaded to the lower end ofthe locking and sealing device. The locking and sealing device holds thecheck valve assembly in the proper position in the landing nipple andseals with the wall of the nipple.

The locking and sealing device includes an elongate tubular mandrel 47having a plurality of laterally movable locking dogs 48 retained inposition thereon by a dog holder or sleeve 49 threaded onto the mandreland surrounding a portion of the upper part thereof in concentric spacedrelation with respect thereto. The dogs have hooks 50 at their upperends engaging over and upwardly facing internal annular shoulder in theupper endof the bore of the dog holder, and also have out wardlyprojecting locking lugs 52 at their lower ends movable laterallyinwardly and outwardly through windows or apertures 53 in the dogholder. The locking lugs have downwardly and outwardly inclined lockingshoulders 54 at their upper ends, and the lugs when expanded laterallyoutwardly through the windows project into the internal locking recess38 of the nipple for engagement with a downwardly facing lock shoulder55 at the upper end of the locking recess. An expander sleeve 56 mountedfor longitudinal sliding movement on the mandrel is moved downwardlyrelative to the mandrel to move the dogs outwardly to expanded position.

A sealing means 53a, shown to be of a plurality of oppositely facingrings of the V or Chevron type, is

disposed on the mandrel and spaced below the locking dogs andv sealsbetween the mandrel and the Wall of the bore of the landing nipple toassure that any fluids flowing within the nipple must pass through themandrel.

A plurality of selective locating and stop keys 64 having downwardlyfacing stop shoulders 65 are provided on the outer surface of themandrel and spaced below the sealing means. The stop keys are movablelaterally on the mandrel and are biased for outward movement into thelocating and stop recess 37 of the landing nipple by means of the keysprings 66 disposed between the stop keys and the mandrel. Lateraloutward movement of the stop keys is limited by the engagement of theupper and lower ends of the keys with upper and lower retaining collars,67 and 68, respectively, on the mandrel. The upper retaining collar 57also serves to retain the sealing means on the tubular mandrel. The stopkeys are manifestly movable inwardly against the biasing of the keysprings toward the mandrel to a non-protruding or retracted position andare able to move outwardly to a projecting position in the locatingrecess of the nipple whereupon the downwardly facing stop shoulders 65of the stop keys engage an upwardly facing annular stop shoulder 69 inthe recess to arrest downward movement of the locking and sealing devicein the landing nipple.

The check valve assembly 44 includes a tubular check valve housing 70connected to the lower end of the mandrel of the locking and sealingdevice. A plunger rod 71 positioned in the housing is longitudinallyrnovable therein and carries a cylindrical plunger or valve head 72threaded to its upper end. -A packing means 73, shown to be of aplurality of rings of packing of the V or Chevron type, is disposed onthe outer surface of the plunger and seals between the plunger and thewall of a counterbore 74 in the lower end of the mandrel 47 of thelocking and sealing device. The engagement of an upwardly facingshoulder 75 on the plunger with a downwardly facing annular shoulder '76at the upper end of the counterbore of the mandrel limits upwardmovement of the plunger in the counterbore.

A check valve spring 77 .on the plunger rod engages an internal annularflange 78 in the lower end of the housing and an annular packingretainer and head lock ring 79 threaded on the plunger rod below theplunger head to bias the plunger upwardly into engagement with theannular shoulder 76 in the counterbore of the mandrel. The packingretainer ring also retains the packing means 73 on the plunger and actsas a jam nut locking the plunger on the plunger rod.

' The check valve housing 76 has a plurality of longitudinal slots 89through its wall so that, when the plunger is moved'downwardly againstthe upward bias of the check valve spring to move the packing means onthe plunger downwardly into the check valve housing, a flow course isopened around the packing means and through the housing. The sealinglips of the packing means 63 face downwardly whereby the'packing meansis adapted to seal in the counterbore of the mandrel against pressuresfrom below.

An equalizing valve 81 is movably positioned in the central through bore82 in the plunger head of the check valve and has an upwardly facingannular shoulder or seat -85 engageable with a downwardly facinginternal annular shoulder or seat 86 in the bore of the plunger toprevent fluid flow through the bore of the plunger head. An equalizingvalve spring 87 surrounds the lower portion of'the equalizing valve andis confined between an external annular flange 88. on the equalizingvalve and the upper end of the plunger rod 71 to bias said valve toclosed position. The upper end of the plunger rod has an axial bore 89therein which communicates with a lateral port 90 extending through thewall of said rod below the packing retainer ring 79 on said rod whereby,when the equalizing valve member 31 is moved downwardly in the plungerhead a flow course is provided between the seats 85 and 86 around thevalve member through the bore 89 in the plunger rod and outwardlythrough the lateral port 90. The equalizing valve 81 has a stem 91extending upwardly from its upper end and projecting above the upper endof the plunger head, the stem being smaller in diameter than the borethrough the plunger whereby a flow course is provided therebetween.

The extension stem of the equalizing valve is engageable by a prong orbar (not shown) which may be lowered through the bore of the locking.and sealing device into the check valve assembly 44 to move the valvedownwardly. When the equalizing valve is moved downwardly in the plungerhead against the upward bias of the spring 87, upward flow may takeplace through the lateral bore 90 and the bore -89-of the plunger,around the equalizing valve member itself and out through the seat 86 inthe upper end of the bore of the plunger head. Pressures above and belowthe equalizing valve may thus be equalized whereby the entire checkvalve assembly 44 may be removed from its position within thecirculating valve by flexible line inserting and removing tools forrepairs or replacement without disturbing the string of drill pipe andwithout danger of having the check valve assembly blown violently fromposition in the nipple by a high pressure below the assembly after thelocking and sealing device 45 has been released.

A plurality of lateral ports 95 are provided through the wall of theupper'part of the outer sleeveas a point slightly below the downwardlyfacing shoulders 30 at the lower ends of the internal splines of thesleeve so that air, debris or fluids within said outer sleeve andsurrounding the splined portion of the inner sleeve may escape as thesleeves are moved to extended position. An O-ring seal means 86 on theouter surface of the inner sleeve at a point below the upwardly facingshoulder 31 seals between the inner and outer sleeves to assist inpreventing the entry of dust or debris into the space between saidsleeves.

A plurality of lateral ports 97 through the wall of the outer sleevejust above the upper sub prevent, in a manner similar to that of theports 95, the trapping of foreign matter or fluids within the outersleeve and below the nipple sub when the inner and outer sleeves aremoved to extended position.

In operation, the circulating valve is assembled in a string of drillpipe with a sufiicient number of drill collars 11a below the valve sothat, when the drill pipe is elevated, the weight of the collars and ofthe drill bit 13 below the valve will be suflicient to cause thetelescoping inner and outer sleeves of the valve to extend despite anyupward force exerted by any fluid pressure from below. In addition, asuflicient number of drill collars are connected above the circulatingvalve to assure that there will be sulficient weight on the circulatingvalve during normal drilling operations to maintain the inner and outersleeves telescoped together and to provide the necessary weight on thedrill bit. The check valve assembly 44 is installed in position in thecirculating valve either while the circulating valve is still at thesurface or by the usual flexible line running tools after thecirculating valve is in place in the drilled hole.

The remainder of the well drilling equipment is installed in thecustomary manner as hereinbefore described in connection with FIGURES land la. Air or gas is circulated downwardly through the string of drillpipe and through the drill bit and thence upwardly through the drilledhole to the surface as drilling progresses, the drill pipe being rotatedby the customary rotary drilling means (not shown) at the surface andthe splined connection between the inner and outer sleeves of thecirculating valve providing for the transmittal of the rotary movementand torque to the drill bit. The flow of drilling gas through thecirculating valve proceeds downwardly through the inner sleeve andthrough the annular space 35a around the upper part of the landingnipple 35 having the check valve therein, thence inwardly through thewindows 36 into the lower part of the nipple below the check valve andthence downwardly through the lower sub to the drill bit and bottom ofthe bore hole.

The circulating valve remains open, as shown in FIG- URES 2, 3 and 4,because the weight of the drill collars 11 and the string of drill pipeabove the valve is sufiicient to maintain the sleeves 35 and 25 in thetelescoped position and the windows '36 are open.

In the event that drilling proceeds into a high-pressure formation suchthat the compressors supplying the drilling air or gas cannot continueto force air or gas downwardly through the drilling string against thehigh formation pressures, drilling is stopped and the string of drillpipe is elevated at the surface. As the drill pipe and upper drillcollars are lifted, the inner sleeve of the circulating valve is raisedwith respect to the outersleeve, since the weight of the outer sleeve,the lower drill collars 11a and the drill bit are suflicient to preventupward movement thereof until the shoulders 30 on the outer sleeve 29engage the shoulder 31 on the inner sleeve, whereupon continued upwardmovement of the inner sleeve lifts the outer sleeve and the drillcollars and drill bit therebelow. With the inner sleeve so movedupwardly to its upper extended position with respect to the outersleeve, the packing means 40 is moved upwardly to a position wherein itseals be- I tween said inner sleeve and the exterior of the landingnipple 35 above the ports 36 and thus closes such ports against fluidflow therethrough. Thus fluids and pressures from below are preventedfrom moving upwardly through the circulating valve by such closing offof the Windows of the nipple and by the check valve assembly 44installed in said nipple.

The remainder of the blowout preventing equipment, i.e., the blowoutpreventer at the surface and the flow line valve 22 are closed,whereupon the high pressures are completely contained within the well.Manifestly, if the drilling head is capable of containing the highformation pressure, it is unnecessary to close the blowout preventers.

If it is desired to resume drilling with a weighted fluid such asdrilling mud, the mud may be pumped downwardly through the drill pipe,the check valve means 46 opening to pressures and flow from above andpermitting downward flow through the circulating valve. Return flow ofgas and, after the well bore has been filled therewith, drilling mud ishad by opening the flow line valve 24. When sufficient mud has beenpumped into the well so that the hydrostatic pressure exerted by the mudis equal to or greater than the pressure of the formation, the formationfluids are retained and the well is killed. The blowout preventer andthe flow line valve 24 may safely be opened. Drilling may thereafter beresumed and may proceed in the normal manner, after the circulatingvalve has been opened by lowering the string of drill pipe until thedrill bit rests on bottom and continuing lowering until the sleeves ofthe circulating valve telescope together in the position shown inFIGURES 2, 3 and 4, to open the windows 36 in the landing nipple topermit flow there through.

If it is desired to remove the check valve for repairs such as may bemade necessary by erosion caused by pumping drilling mud downwardlytherethrough, a flexible line pulling tool mechanism including aretrieving or pulling tool having a prong (not shown) for depressing theequalizing valve stem 91 is lowered through the drill pipe into thecirculating valve, the prong of the pulling tool engaging and openingthe equalizing valve to permit flow therethrough to assure that thepressures above and below the check valve are the same. The pulling toolgrasps the external annular flange 92 at the upper end of the expandersleeve 52, and an upward pull on the expander sleeve moves the sameupwardly to release the locking dogs for inward movement. A continuedupward pull on the sleeve lifts the entire locking and sealing device 45together with the attached check valve 46 upwardly out of the landingnipple. The beveled upwardly facing locking shoulders 50 of the lockingdogs engage the downwardly facing lock shoulder 51 of the recess 38 ofthe nipple to cam the dogs inwardly, and the beveled upwardly facingshoulders 83 and 84 of the stop keys engage the shoulder at the upperend of the recess or groove 37 to cam the stop keys inwardly against'theoutward bias of the key springs.

The check valve may be reinstalled following any necessary repairs, orit may be left out of the circulating valve, if desired, if drilling isto be continued with a weighted drilling fluid. With the check valveremoved, the bore through the drill pipe is unobstructed, and anydesired well tools may be passed downwardly through said pipe and thelanding nipple. Alternatively, other devices may he landed and suspendedin the landing nippie, if desired. 1

It will thus be seen that a circulating valve has been shown anddescribed which may be installed in a string of drill pipe and whichdoes not interfere with the normal downward flow of a drilling fluidtherethro'ugh. It will further be seen that the circulating valve may beeasily and readily closed to flow from below simply by raising the drillpipe to prevent pressure or flow from below from passing upwardlythrough the circulating valve.

It will particularly be seen that the circulating valve is soconstructed that the weight of the string of drill collars and the drillbit therebelow will hold the sleeve members of said valve in extendedposition closing off flow through the valve, and that the weight of thedrill pipe and'drill collars above the valve hold the valve in openposition when the drill pipe string thereabove is lowered to move thesleeve members to the telescoped or collapsed position whereby theweight of the drill string may be applied to the bit while the valve isopen.

It will be seen that the circulating valve, by means of the splines 27and 28 of the inner and outer sleeves, respectively, engage one anotherwhereby the torque necessary for rotary drilling may be transmitted bythe circulating valve.

It will further be seen that downward flow may be obtained through thecirculating valve at any time, even though the device has been closedagainst pressure from below, simply by pumping downwardly through acheck valve installed in the landing nipple.

it also will be seen that the check valve may be removed for repairs andservice by flexible line tools without disturbing the string of drillPipe, and may similarly be replaced. It will be seen that an equalizingvalve means in the check valve assembly may be actuated before removingsaid check valve assembly in order to assure that no upward pressuredifferential exists which may suddenly blow said valve assembly upwardlywhen it is released from locked position in the landing nipple.

It will be seen that, when the check valve assembly has been removedfrom the landing nipple, the opening through the circulating valve is ofa size approximating that through the string of drill pipe.

It will also be seen that a circulating valve has been shown anddescribed in which the sealing surfaces of said valve are not subject toerosion by the stream of drilling fluid.

The foregoing description of the invention is explanatory only, andchanges in the details of the construction illustrated may be made bythose skilled in the art, Within the scope of the appended claims,Without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

l. A well tool including: an elongate tubular housing; an elongatetubular body telescoped downwardly into said housing for limitedlongitudinal movement themwithin; means on said body and said housingcoengageabie to prevent relative rotation between said housing and saidbody about their longitudinal axes; a tubular mandrel in the lower endof said housing and extending upwardly into the bore of said body, theouter dimension of said mandrel being substantially less than the insidediameter of the bore of said body to provide a flow passagetherebetween; means providing a lateral port through said mandrelintermediate the ends of said mandrel; and packing means disposedbetween said body and said mandrel to seal between said body and saidmandrel below said port means when said body and said housing are tele-vscoped together and to seal above said port means-when said body andsaid housing are moved to extended position.

2. A well tool including: an elongate tubular housing; a tubular bodytelescoped downwardly into said housing for limited longitudinalmovement therewithin; means on said body and said housing coengageableto prevent relative rotation between said housing and said body abouttheir longitudinal axes; an elongate tubular mandrel in the lower end ofsaid housing and extending upwardly into the bore of said body, theouter dimension of said mandrel being substantially less than the insidediameter of the bore of said body to provide a flow passagetherebetween; means providing a lateral port through said mandrelintermediate the ends thereof; packing means disposed be tween said bodyand said mandrel to seal between said i Alum-u body and said mandrelbelow said port means when said body and said housing are telescopedtogether and above said port means when said body and said housing aremoved apart to extended position; and a check valve removably mounted insaid mandrel, said check valve opening only to flow downwardlytherethrough.

3. A well tool comprising: a pair of telescopically connected upper andlower tubular members adapted to be connected in a rotary drill pipestring; means on each of said tubular members coengageable so thatrotation of one of said members rotates the other of said members, saidmeans providing for limited longitudinal movement of said membersrelative to each other; and a valve mechanism carried by said membersand having parts movable with said tubular members to positions to opento establish communication between said upper and lower sections ofdrill string when said tubular members are telescoped together and toclose when said tubular members are extended, said means havingcoengageable means permitting application of a downwardly directed forcethrough said upper tubular member to said lower tubular member duringdrilling operations.

4. A well tool of the character set forth in claim 3 including: abushing in the lower end of said upper member; a tubular nipple in thelower end of said lower member extending upwardly through said bushing;packing means in said bushing sealing with said nipple; means providinga lateral port in said nipple, said port being positioned below thepacking in said bushing when said tubular members are extended andmovable to a position above the packing in said bushing when saidtubular members are telescoped together; and plug means removablyinstalled in said nipple.

5. A circulating valve for use in a string of pipe in a well, said valveincluding: a lower tubular member and an upper tubular member telescopedinto said lower' tubular member; means connecting said tubular membersfor limited longitudinal movement relative to each other betweenextended and telescoped positions; means for connecting said tubularmembers in a string of well drill pipe; key means on said tubularmembers coengageable to prevent rotation of said tubular membersrelative to one another about their longitudinal axes; a tubular nippleconnected with said lower member extending upwardly into said uppermember; means providing a flow course between the outer surface of saidnipple and the interior of said upper member; sealing means on saidnipple and said upper member providing a seal therebetween; meansproviding a lateral port in said nipple above its lower end; saidsealing means being disposed to seal be tween said upper member and saidnipple below said port when said upper and lower members are incollapsed position to provide a flow passage from said lower memberupwardly and outwardly through said port into said upper member, saidpacking also being disposed to seal above said port when said upper andlower members are in extended position to close off the flow passagefrom said lower member through said port into said upper member; and acheck valve removably positioned in said nipple, said check valve beingopenable to permit flow downwardly therethrough from said upper memberto said lower member and closable to prevent fiow in the oppositedirection therethrough.

6. A circulating valve for use in a string of pipe in a well, said valveincluding: a lower tubular member and an upper tubular member telescopedinto said lower tubular member; means connecting said tubular membersfor limited longitudinal movement relative to each other betweenextended and telescoped positions; means for connecting said tubularmembers in a string of well drill pipe; key means on said tubularmembers coengageable to prevent rotation of said tubular membersrelative to one another about their longitudinal axes; a tubular nippleconnected with said lower member and with its bore communicating withthe bore of said lower member, said nipple extending upwardly into saidupper member; means providing a lateral flow port from the interior tothe exterior of said nipple above its lower end; means providing a flowcourse upwardly from said lateral flow port between the outer surface ofsaid nipple and the interior of said upper member; sealing means on saidnipple and said upper member providing a seal therebetween; said sealingmeans being disposed to seal between said upper member and said nipplebelow said port when said upper and lower members are in collapsedposition to provide a flow passage from said lower member upwardly andoutwardly through said port into said upper member, said packing alsobeing disposed to seal above said port when said upper and lower membersare in extended position to close off the flow passage from said lowermember through said port into said upper member; and means closing thebore of said tubular nipple above said lateral port.

7. A circulating valve of the character set forth in claim 6 wherein:the bore of said tubular nipple is open to the bore of the upper tubularmember above the upper end of said nipple and said tubular nipple isprovided with locking and sealing surfaces in its bore; and the meansfor closing the bore of said nipple is a removable plug member havinglocking and sealing means coengageable with the locking and sealingsurfaces in the bore of the nipple.

8. A circulating valve of the character set forth in claim 6 wherein:the means closing the bore of the tubular nipple above the lateral portincludes a check valve openable to permit flow downwardly through thenipple from the upper member to the lower member and closable to preventsuch flow.

9. A circulating valve of the character set forth in claim 7 wherein:the removable plug member includes a I check valve openable to permitflow downwardly through the nipple from the upper member to the lowermember and closable to prevent such flow.

10. A circulating valve of the character set forth in claim 9 wherein:the check valve is provided with a pressure equalizing means openable topermit equalization of fluid pressures above and below said check valveto facilitate opening said check valve and removal of said plug memberfrom within said nipple.

References Cited in the file of this patent UNITED STATES PATENTS1,617,659 Whinnen Feb. 15, 1927 1,799,411 Davis Apr. 7, 1931 1,807,837Fortune June 2, 1931 2,127,728 Grant Aug. 23, 1938 2,148,327 Smith et a1Feb. 21, 1939 2,704,579 Brown Mar. 22, 1955 2,798,559 Fredd July 6, 1957

